The present invention concerns an electric plug, particularly of the kind to be used, in a cigarette lighter socket as used in automobiles etc.
Such plugs include a peripheral pole (normally minus or ground) and a central pole (normally plus). The peripheral pole is generally a metal wire or strip extending along a substantial portion of the plug length, thereby obtaining a relatively long contact length with the interior of the socket. The central pole is generally a cylindrical contact rod that is spring loaded in order to maintain contact with a plus bottom pole of the socket even in case of smaller axial displacements of the plug. The spring load is generally provided by a compression spring, such as a leaf spring or a helical spring. In use, the electrical current is lead through the spring to a connector member that in turn is connected to an electric lead. This is not a problem in low current applications, such as normal flashlights, radio equipment, tape recorders etc., but when it comes to high current applications, such as winches or powerful flashlights, the current load may lead to overheating of the spring such that it loses its spring properties, or, even melts and breaks the electric circuit.
The present invention has as its object to provide a new male plug that does not suffer from this drawback. According to the present invention, there is provided an electric plug having a pole including a contact rod having a forward end and a rear end, a connector member and spring means interposed between said contact rod and said connector member to urge said contact rod in a forward direction, wherein said contact rod is provided in its rear end with an axial extension and said connector member is provided with a bore slidingly receiving a rear free end of said extension.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific example, while indicating a preferred embodiment of the invention, is given by way of example only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.